The role of cAMP-dependent protein kinase A in the formation of long-term memory in Bactrocera dorsalis

The cAMP-dependent protein kinase A(PKA)signaling pathway has long been considered critical for long-term memory(LTM)formation.Previous studies have mostly focused on the role of PKA signaling in LTM induction by multiple spaced conditioning with less attention to LTM induction by a single conditioning.Here,we conducted behavioral-pharmacology,enzyme immunoassay and RNA interference experiments to study the role of the PKA signaling pathway in LTM formation in the agricultural pest Bactrocera dorsalis,which has a strong memory capacity allowing it to form a two-day memory even from a single conditioning trial.We found that either blocking or activating PKA prior to conditioning pretreatment affected multiple spaced LTM,and conversely,they did not affect LTM formed by single conditioning.This was further confirmed by enzyme-linked immunosorbent assay(ELISA)and silencing of the protein kinase regulatory subunit 2 and catalytic subunit 1.Taken together,these results suggest that activating PKA during memory acquisition helps to induce the LTM formed by multiple spaced conditioning but not by a single conditioning.Our findings challenge the conserved role of PKA signaling in LTM,which provides a basis for the greater diversity of molecular mechanisms underlying LTM formation across species,as well as possible functional and evolutionary implications.

Deep Exploration of Bifidobacteria through Metabolomics Study

Bifidobacteria are probiotic bacteria with multiple health-promoting properties for human being. The global market for probiotics, especially for bifidobacteria is booming. However, the entire market is still at an early stage as there is nearly no fine products developed yet except the whole bacterial cells. The maturation of metabolomics technologies make it possible to study complex mixture with high-throughput, comprehensive maps and libraries. Therefore, we prospect that metabolomics studies mainly based on liquid/gas chromatography-mass spectrometry (LC/GC-MS) can deepen our understanding in detail during the study of metabolic mechanisms of bifidobacteria. These studies can be conducted at three phases, including non-targeted, targeted metabolomic analysis of bifidobacteria, and specific metabolites production through metabolic engineering and fermentation. Metabolomic studies of bifidobacteria will allow us to fully explore their metabolic mechanisms and to utilize metabolites that contribute to human health. In particular, bifidobacteria derived conjugated linoleic acids and bacteriocins are two kinds of fined products that may have great potentials in the future and can be used as food additives.

Bioinformatic Survey of S-Layer Proteins in Bifidobacteria

Surface layer (S-layer) proteins are one of the most commonly observed cell envelope components in both Archaea and Bacteria. It has versatile functions and holds considerable application potential in biotechnology. Bifidobacteria are representative probiotics conferring health promoting properties. However, there is little study of S-layer in bifidobacteria yet. The distribution and characteristics of S-layer in bifidobacteria are unknown. In this study, search for S-layer protein in the identical protein groups in NCBI yielded 49 hits belonging to bifidobacteria. These proteins were annotated as either “S-layer (domain) protein” or “putative S-layer (y) domain protein” that distributed among 26 species of Bifidobacterium genus. Multiple alignments suggest S-layer proteins are relatively conservative. Phylogenetic analysis of 24 S-layer (domain) protein sequences groups them into three distinct clusters, with the majority species in Cluster-2. S-layer (domain) protein has a universe motif DUF4381, though its function is unknown. Meanwhile, two other motifs CARDB and EphA2_TM involved in cell adhesion and cell signaling respectively, presented in most S-layer (domain) protein in bifidobacteria. All S-layer proteins have a typical N-terminal Sec-dependent signal peptide and a C-terminal trans-membrane region. Homological modeling of representative S-layer proteins from each cluster revealed a few unique structural features. All representative S-layer proteins have a plenty of β-meander motif that exclusively composed by β-barrel structural architectures linked together by hairpin loops.

Function of Ca^(2+)-/calmodulin-dependent protein kinase Ⅳ in Ca^(2+)-stimulated neuronal signaling and behavior

The activity of Ca2+/calmodulin-dependent protein kinase IV(Ca MKIV) is sensitive to activity-dependent changes in the level of intracellular Ca2+.Following neuronal stimulation,the activation of Ca MKIV may trigger synaptic modifications and transcriptional responses,both of which are involved in regulating cognitive and emotional behavior.Here,we used Ca MKIV knockout(KO) neurons and mice to examine the function of Ca MKIV in Ca2+-stimulated intracellular signaling and animal behavior,respectively.Following NMDA receptor activation or membrane depolarization,the up-regulation of CREB(c AMP responsive element binding protein) and its target gene Bdnf(brain-derived neurotrophic factor) was intact in cortical neurons obtained from Ca MKIV KO mice.Ca MKIV KO mice displayed severe impairment in contextual fear memory but normal locomotor activity and anxiety level in the contextual training chamber.Although Ca MKIV KO mice showed normal memory in the standard passive avoidance task,they were defective in learning the temporal dissociative passive avoidance task.As indicated by the light/dark test and marble-burying test data,Ca MKIV KO mice showed less anxiety and normal perseveration.In the voluntary wheel-running test,Ca MKIV KO mice showed normal running time and distance but higher maximal running speed.Our results demonstrate the function of Ca MKIV in regulating different forms of fear memory,anxiety,and certain aspect of motor function.

Chemical solution route to synthesize claw-like ZnO nanorod array and its optical properties

By using a low-cost and facile hydrothermal method, a peculiar claw-like ZnO nanorod array is successfully synthesized. The hydrothermal growth is done in an aqueous solution with equimolar zinc acetate(ZAc, Zn(CH3COO)2·2H2O) and hexamethylenetetramine(HMTA, C6H12N4). The obtained ZnO nanorod array is characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM) and transmission electron microscopy(TEM). The results indicate that the nanorods are high-quality monocrystals. The photoluminescence(PL) spectrum is performed to investigate the optical properties of this product.

Anti-obesity effects of angiotensin converting enzyme inhibitor are mediated by brown adipose tissue activation

Obesity is characterized with the disorder of energy metabolismwhich often causes various complications such as insulin resis-tance and type 2 diabetes. A recent estimate performed by WorldHealth Organization （WHO） in 2014 showed that up to 0.6 billionindividuals had suffered from obesity, indicating that the drugscreening against obesity is quite crucial. In mammals, there aretwo types of adipose tissues.